Stay longer in St. LuciaThe Landings in St. Lucia is offering a free fourth night on three-night stays between Jan. 5 and April 30. The $1,100 deal includes a two-bedroom suite, a $100 resort credit, and kayak and sailboat rental. Book by Dec. 31.Contact: Rockresorts.com

Shark excursionAdventure-seekers can swim with Caribbean reef sharks and dive 2,000 feet in a submarine to see prehistoric six-gill sharks in Roatan, Honduras. Shark Diver offers an eight-day all-inclusive trip for $3,300 per person. Contact: Sharkdiver.com

Sail the CaribbeanIn March and April, Canadian Sailing Expeditions’ six-night trips from St. Maarten to Antigua start at $1,284 double, plus tax. Includes hands-on sail training on the Windjammer vessel.Contact: Canadiansailingexpeditions.com

Rent Steve Martin’s villaThis spring, actor Steve Martin purchased the four-bedroom Villa au Soleil on St. Barthelemy. The half-acre property—with views of St. Jean Bay, a caretaker’s house, a pool, and a gazebo—rents for $16,000 to $28,000 per week.Contact: Stbarth.com